6 Metaxalone Side Effects and How to Manage Them

Metaxalone is a muscle relaxer. It may be prescribed if you need short-term relief from muscle pain or stiffness. Like all muscle relaxers, it’s meant to be used alongside nonmedication treatments, like rest and physical therapy. 

Metaxalone shares many of the same side effects as other muscle relaxers such as cyclobenzaprine (Flexeril). Some research shows it may be better tolerated. Still, metaxalone side effects can happen. Knowing what to watch for can help keep you safe.

Metaxalone side effects at a glance

Some metaxalone side effects are more common than others. Common side effects can often be handled at home, since they tend to be mild.

Promotion disclosure

Metaxalone

Avg retail price

$143.66(Save 79.42%)

GoodRx discount

$29.56

See all discounts

How it works

Use GoodRx to find medications, pharmacies, and discounts.

GoodRx discounts can help you pay less for your prescription.

Bring your free coupon or savings card to the pharmacy.

Typically mild metaxalone side effects include:

• Drowsiness

• Dizziness

• Irritability

• Headache

• Gastrointestinal problems, such as nausea and vomiting

Severe side effects, although rare, may require a phone call to your prescriber. In some cases, they may even warrant emergency care. Rare but serious metaxalone side effects include:

• Serotonin syndrome (a buildup of the chemical serotonin in the body)

• Slowed breathing when combined with other substances that can affect breathing, including alcohol

• Decreased levels of certain blood cells

Below, we’ll go into more detail about six of these metaxalone side effects.

1. Drowsiness

Drowsiness is one of the most common side effects of muscle relaxers, including metaxalone. This is because muscle relaxers have sedative effects on the brain, which make you feel sleepy.

You’re less likely to become drowsy with metaxalone compared to other muscle relaxers. But taking higher doses can increase the risk of drowsiness. Taking metaxalone with food can also increase the risk of this side effect, because food enhances metaxalone absorption. So if you’re experiencing drowsiness or dizziness, try taking your metaxalone doses without food.

Feeling drowsy can affect your ability to do activities that require you to be alert. For example, you shouldn’t drive or operate machinery when you first start taking metaxalone. Wait until you know how metaxalone affects you before doing these activities.

If metaxalone is causing sleepiness, you can try boosting your energy levels by getting plenty of rest, exercising regularly, and eating nutrient-rich foods. But if drowsiness doesn’t improve, let your healthcare team know, especially if it’s interfering with your daily activities. You may need a lower dose or to switch to another medication altogether. 

Taking metaxalone with other substances that can cause drowsiness can make this side effect worse. Examples include opioids, benzodiazepines, and alcohol. More seriously, this combination can slow your breathing and increase your risk of an overdose. In most cases, it’s best to avoid taking these substances if you’re prescribed metaxalone.

2. Dizziness

Dizziness is another common metaxalone side effect. It may improve over time as your body gets used to the medication. Still, dizziness is another reason to avoid activities that require focus when you first start taking this medication. 

Dizziness can also increase your risk of falls, especially if you’re 65 or older. In fact, it’s best for older adults to avoid muscle relaxers altogether if possible.

If you’re feeling dizzy from metaxalone, sit or lie down until it improves. And make sure you have something solid to hold onto when changing positions. Drinking plenty of water throughout the day can also help, as dehydration may be contributing to your dizziness.

If your dizziness continues, talk to your prescriber. There could be several other causes, including low blood pressure and other medical conditions.

3. Irritability

Feeling irritable is another possible side effect of metaxalone. But since irritability can be caused by several things, it can be hard to know if it’s from metaxalone or something else.

Regardless, there are ways to cope with irritability. For example, exercising and taking several slow, deep breaths can help you feel more calm. However, if you feel your irritability is related to metaxalone, talk with your prescriber. They can help discuss possible solutions, which might include reducing your dose or switching to another medication.

4. Headache

Headaches can happen with metaxalone treatment. While they’re unpleasant, they may go away on their own. 

In the meantime, you can try some things at home to relieve headaches. These include staying hydrated, reducing stress, and exercising. Taking over-the-counter pain medications can also help. Examples include ibuprofen (Advil, Motrin), naproxen (Aleve), and acetaminophen (Tylenol). But check with your prescriber before trying these medications. They aren’t the best option for everyone. 

If your headaches aren’t going away or if they’re getting worse, let your healthcare team know. Several lifestyle habits, medical conditions, and medications can cause headaches, so it may not be related to metaxalone specifically.

5. Nausea and other gastrointestinal problems

Gastrointestinal (GI) problems like nausea, vomiting, and an upset stomach are possible metaxalone side effects. 

Many health conditions and lifestyle habits can cause nausea. It’s also a common side effect of many medications. So check with your prescriber and pharmacist to see if other medications you take may be causing nausea. Taking several medications at once that can cause nausea makes it more likely.

If you’re experiencing nausea, there are a few things you can try at home to find relief. Taking metaxalone with food, eating smaller (but more frequent) meals throughout the day, and avoiding spicy or fried foods can help calm an upset stomach. Staying well-hydrated can also help.

If your nausea or other GI side effects don’t improve, talk to your prescriber. You may need a metaxalone dosage adjustment or to switch to another medication.

6. Serotonin syndrome

Serotonin syndrome is a condition that happens when there’s too much serotonin in the brain. Serotonin is a chemical that regulates body functions like mood, sleep, and digestion.

Serotonin syndrome is rare but can be dangerous (and rarely, life-threatening). But taking metaxalone on its own, at approved doses, won’t cause serotonin syndrome. Taking multiple medications that increase serotonin, or taking too much metaxalone, is what puts you at risk of this side effect.

Give your prescriber and pharmacist a list of the medications you take. They can let you know if you’re at risk of serotonin syndrome. Examples of medications that can increase serotonin levels include:

• Selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft)

• Serotonin and norepinephrine reuptake inhibitors (SNRIs), such as duloxetine (Cymbalta)

• Tricyclic antidepressants, such as amitriptyline

• Some opioids, such as tramadol (ConZip, Qdolo)

• Triptans (headache medications), such as sumatriptan (Imitrex)

Mild symptoms of serotonin syndrome may include sweating and tremors. In severe cases, confusion, hallucinations, and seizures are possible. If you’re experiencing mild symptoms, call your prescriber’s office immediately. If you have any severe symptoms, seek emergency care.

Why trust our experts?

Written by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Alex Brewer, PharmD, MBA

Alex Brewer, PharmD, MBA, is a licensed pharmacist specializing in chronic disease and health and wellness. Upon completing his residency, he worked in the managed care field, conducting medication therapy management and adherence counseling sessions with Medicaid, Medicare, and private insurance patients, before transitioning to a career in medical writing.

Our editorial standards

Meet our experts